Preliminary results from the D0 experiment on jet production with rapidity
gaps in ppˉ collisions are presented. A class of dijet events with a
forward rapidity gap is observed at center-of-mass energies s = 1800
GeV and 630 GeV. The number of events with rapidity gaps at both center-of-mass
energies is significantly greater than the expectation from multiplicity
fluctuations and is consistent with a hard single diffractive process. A class
of events with two forward gaps and central dijets are also observed at 1800
GeV. This topology is consistent with hard double pomeron exchange. We also
present proposed plans for extending these analysis into Run II through the use
of a forward proton detector.Comment: plain tex, 5 pages, 2 figure